The unpopularity of British politicians is hardly new. We have enjoyed complaining about our elected representatives for almost as long as we have been monitoring the balance of power on continental Europe and moaning about the weather. When William Hogarth painted The Humours of an Election, his four-canvas masterpiece of 1755, it depicted a mid-18th century contest as a grotesque carnival of vote-rigging, drunkenness and cynicism. Many modern voters would say that not much has changed. In these terms the currently all-pervasive anti-politics mood is merely part of an ancient continuum.

This time, however, there are powerful reasons for saying it could be different. The British system is fragmenting in such novel, curious and entertaining ways that it is questionable whether it can be mended. Both of the main parties are struggling to get anywhere close to 40 per cent of the vote. Meanwhile, the Tory Right has split, with the rise of the Eurosceptic UKIP. All that its leader Nigel Farage need do at the next general election is get somewhere upwards of 6 per cent of the vote to cost the Tories seats by letting other parties through. There is a coalition, and there may well be another after 2015.

Haven't we been here before, or somewhere similar, in terms of the disintegration and potential death of the party system? Thirty years ago, in the election held in June 1983, Margaret Thatcher and the Conservatives stormed to victory with more than 40 per cent of the vote, and her Labour opponents were smashed, although not simply in the traditional sense of being defeated. They were pushed down well below 30 per cent, the party's worst-ever showing, and there, biting on their heels and surging to fill the gap, came the parties of the centrist Alliance, made up of the old Liberals and the then new Social Democratic Party.

The Alliance, it was said by many commentators, was about to "break the mould" and usher in a three-party system. But in 1983 two young Labour MPs were elected with different ideas. Tony Blair and Gordon Brown were at that point united in rejecting defeatism and believing that if the Labour Party modernised itself sufficiently — changing some of its policies and its marketing — then it could win handsomely again. In 1997 Blair's New Labour duly got 43 per cent of the vote and a thumping overall majority. Their example demonstrated that revival is possible.